Check for record in Table
I am trying to check for the existence of a record in a SQL table in a if statement, I was trying to us开发者_开发知识库e .Count() but now understand that it won't work as it will return the total amount of all records in the table.
// If the current user does not exist in the Database, then add the user
if (staffdb.Staffs.Single(s => s.Staffname == user).Count() == 0)
{
}
I'm a bit of a novice when it comes to this but I've done a bit of searching the net and can't seem to find anything to go off.
The correct solution is:
if (!staffdb.Staffs.Any(s => s.Staffname == user))
{
// ...
}
This ensures that the database will stop looking once it finds one. If you use .Where()
followed by .Count()
, it will potentially go through the entire table and retrieve a longer list than necessary.
// If the current user does not exist in the Database, then add the user
if (staffdb.Staffs.SingleOrDefault(s => s.Staffname == user) == null)
{
}
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